A Method to Optimize Stability and Wheel Wear in Railway Bogies

Mazzola, L.,Alfi, S.,Bruni, S. The Korean Society for Railway 2010 International Journal of Railway Vol.3 No.3

In this paper, a procedure is proposed to optimize bogie suspension parameters in view of minimizing wheel wear produced by curve negotiation, though meeting stability requirements. The problem is dealt with in the form of a constrained minimization problem, in which wheel wear evaluated over a given service scenario is introduced as the cost function to be minimized, and the requirements on vehicle stability are formulated in terms of constraints. The procedure is applied to the case of a non-powered passenger car for high-speed service, and the results obtained are discussed. It is shown that long wheelbase bogie may provide better overall performances than bogies having comparatively short wheelbase. Furthermore, a sensitivity analysis is performed, to define the effect on the optimization results of improving the performances of the yaw dampers in the bogie and of using a different wheel profile.

A Method to Optimize Stability and Wheel Wear in Railway Bogies

L. Mazzola,S. Alfi and S. Bruni 한국철도학회 2010 International Journal of Railway Vol.3 No.3

In this paper, a procedure is proposed to optimize bogie suspension parameters in view of minimizing wheel wear produced by curve negotiation, though meeting stability requirements. The problem is dealt with in the form of a constrained minimization problem, in which wheel wear evaluated over a given service scenario is introduced as the cost function to be minimized, and the requirements on vehicle stability are formulated in terms of constraints. The procedure is applied to the case of a non-powered passenger car for high-speed service, and the results obtained are discussed. It is shown that long wheelbase bogie may provide better overall performances than bogies having comparatively short wheelbase. Furthermore, a sensitivity analysis is performed, to define the effect on the optimization results of improving the performances of the yaw dampers in the bogie and of using a different wheel profile.

Creativity in Music

Guerino Mazzola(궤리노 마촐라),Joomi Park(박주미) 한국전자음악협회 2011 에밀레 Vol.9 No.1

이 글에는 수학적 음악 이론과 음악 정보학의 구조유형적(functorial) 접근방법(구조함수Functor란 수학의 범주들 사이에 정해진 구조적 유형을 의미함)이 소개되었다. 이 방법이 음악적 제스처의 이론과 이를 루바토 소프트웨어에서 실행하는데 사용되었는데, 제스처 이론에 입각하여 음악적으로 분석하는 방식으로 설명한다. 그 다음으로 음악적 창조성에 대한 수학적 접근 방법을 소개하였는데, 이 방법은 요네다의 보조 정리를 사용하여 베토벤의 피아노 소나타 op. 109의 3악장에 나오는 여섯 개의 변주곡을 이해하는 것이다. 끝으로, 이러한 수학적 모델과 이를 현대 대위법 이론에 적용시키는 것을 기호학적으로 일반화하면서 이 글은 결론을 맺는다. The functorial approach (functors are structure-preserving maps between mathematical categories) to mathematical music theory and of musical gestures and its implementation in the Rubato software. We discuss musical analyses based upon gestural theory. Then the mathematical approach to musical creativity is introduced. Using Yoneda’s lemma these ideas are applied to understand Beethoven’s six variations of the third movement of sonata op. 109. The paper concludes with the semiotic generalization of this mathematical model and its application to a theory of contemporary counterpoint.

Surface gloss, gloss retention, and color stability of 2 nano-filled universal resin composites

Molina Gustavo Fabián,Cabral Ricardo Juan,Mazzola Ignacio,Burrow Michael 대한치과보존학회 2022 Restorative Dentistry & Endodontics Vol.47 No.4

Objectives This study compared the surface gloss (SG), gloss retention (GR), and color stability (CS) of 2 universal resin composites after chemical (CA) and mechanical (MA) aging. Materials and Methods Twenty disc-shaped samples of G-ænial A´Chord (GC-Europe) and Filtek Universal (3M-ESPE) were polished with sequential abrasive papers. For CA, specimens were stored in 1 mL of 75% ethanol for 15 days at 37°C, and readings (SG, GR, and CS) were obtained at baseline and 5, 10, and 15 days. For MA, specimens were subjected to 10,750 simulated brushing cycles. SG and CS were evaluated after every 3,583 cycles. SG was measured with a glossmeter (geometrical configuration: 60°), and values were expressed in gloss units. Color was measured with a spectrophotometer using the CIE-L*a*b* color system. The Student’s t-test, 1-way analysis of variance, and Scheffé test were used for statistical analysis (α = 0.05). Results G-ænial presented significantly higher SG values than Filtek (p = 0.02), with GR reductions of 5.2% (CA) and 5.3% (MA) for G-ænial and 7.6% (CA) and 7.2% (MA) for Filtek. The aging protocol had no statistically significant effect on SG or GR (p = 0.25) from baseline to the final readings. G-ænial–MA presented the lowest color difference (∆E = 1.8), and G-ænial–CA and Filtek–CA had the largest changes (∆E = 8.6 and ∆E = 11.8, respectively). Conclusion G-ænial presented higher SG values and better CS. Both restorative materials demonstrated acceptable GR and CS. Aging protocols impacted these properties negatively. Objectives This study compared the surface gloss (SG), gloss retention (GR), and color stability (CS) of 2 universal resin composites after chemical (CA) and mechanical (MA) aging. Materials and Methods Twenty disc-shaped samples of G-ænial A´Chord (GC-Europe) and Filtek Universal (3M-ESPE) were polished with sequential abrasive papers. For CA, specimens were stored in 1 mL of 75% ethanol for 15 days at 37°C, and readings (SG, GR, and CS) were obtained at baseline and 5, 10, and 15 days. For MA, specimens were subjected to 10,750 simulated brushing cycles. SG and CS were evaluated after every 3,583 cycles. SG was measured with a glossmeter (geometrical configuration: 60°), and values were expressed in gloss units. Color was measured with a spectrophotometer using the CIE-L*a*b* color system. The Student’s t-test, 1-way analysis of variance, and Scheffé test were used for statistical analysis (α = 0.05). Results G-ænial presented significantly higher SG values than Filtek (p = 0.02), with GR reductions of 5.2% (CA) and 5.3% (MA) for G-ænial and 7.6% (CA) and 7.2% (MA) for Filtek. The aging protocol had no statistically significant effect on SG or GR (p = 0.25) from baseline to the final readings. G-ænial–MA presented the lowest color difference (∆E = 1.8), and G-ænial–CA and Filtek–CA had the largest changes (∆E = 8.6 and ∆E = 11.8, respectively). Conclusion G-ænial presented higher SG values and better CS. Both restorative materials demonstrated acceptable GR and CS. Aging protocols impacted these properties negatively.

The Glycemic Index of Indica and Japonica Subspecies Parboiled Rice Grown in Italy and the Effect on Glycemic Index of Different Parboiling Processes

Mariangela Rondanelli,Riccardo Anselmo Ferrario,Gaetan Claude Barrile,Davide Guido,Clara Gasparri,Cinzia Ferraris,Alessandro Cavioni,Francesca Mansueto,Giuseppe Mazzola,Zaira Patelli,Gabriella Peroni 한국식품영양과학회 2023 Journal of medicinal food Vol.26 No.6

Rice is generally considered a high-glycemic index (GI) food, but numerous studies show that parboiling reduces the GI. There are no studies on GI of Indica and Japonica subspecies parboiled rice grown in Italy. The aim of this study was (1) to evaluate GI in different varieties of parboiled rice (ribe, white and brown long B, basmati, black, red, roma, and arborio); (2) to evaluate GI of same variety of rice subjected to different rice parboiling processes (parboiled ribe and parboiled long B with two different methods: flora and conventional method); (3) to evaluate GI of two by-products of parboiled rice: white and brown rice cake. Participants were 10 healthy individuals (20–30 years old, body mass index 18.5–25 kg/m2). Proximate composition and GI were determined by using standard methods. All parboiled rice assessed is low-GI (brown long B 48.1 ± 6.4 by flora method, ribe 52.0 ± 1.8 GI by flora method, black rice 52.3 ± 7.6 by flora method, long B 52.4 ± 3.9 by flora method, long B 53.4 ± 5.1 by conventional method, ribe 54.4 ± 4.3 GI by conventional method, Roma 54.4 ± 7.9 GI by flora method, and arborio 54.4 ± 7.9 GI by flora method), except red rice that is of medium-GI (56.1 ± 7.0 GI), and both classic and brown cakes that are high-GI (respectively, 83.3 ± 8.9 GI and 102.2 ± 5.5 GI). Parboiled rice is low-GI and so is favorable for the dietary management of metabolic disorders and celiac disease. Clinicaltrials.gov (NCT05333081).

Ubiquitous formation of bulk Dirac cones and topological surface states from a single orbital manifold in transition-metal dichalcogenides

Bahramy, M. ,S.,Clark, O. ,J.,Yang, B.-J.,Feng, J.,Bawden, L.,Riley, J. ,M.,Marković,, I.,Mazzola, F.,Sunko, V.,Biswas, D.,Cooil, S. ,P.,Jorge, M.,Wells, J. ,W.,Leandersson, M Nature Publishing Group, a division of Macmillan P 2018 NATURE MATERIALS Vol.17 No.1

Transition-metal dichalcogenides (TMDs) are renowned for their rich and varied bulk properties, while their single-layer variants have become one of the most prominent examples of two-dimensional materials beyond graphene. Their disparate ground states largely depend on transition metal d-electron-derived electronic states, on which the vast majority of attention has been concentrated to date. Here, we focus on the chalcogen-derived states. From density-functional theory calculations together with spin- and angle-resolved photoemission, we find that these generically host a co-existence of type-I and type-II three-dimensional bulk Dirac fermions as well as ladders of topological surface states and surface resonances. We demonstrate how these naturally arise within a single p-orbital manifold as a general consequence of a trigonal crystal field, and as such can be expected across a large number of compounds. Already, we demonstrate their existence in six separate TMDs, opening routes to tune, and ultimately exploit, their topological physics.